ギャスケット

• 今回楽過ぎでは…？
• ただ、x&y>0より先にx|y!=x+yが出てきてしまったのがつらい。
  • ※ベン図を描くとわかりますが、(x|y)==(x&y)|(x^y)です。

Ruby

tyama_henae15.rb

#!/usr/bin/env ruby
#http://nabetani.sakura.ne.jp/hena/orde15nohil/
#http://qiita.com/Nabetani/items/705fa83cfbf20377b92f

def num2place(n)
    x=y=0
    z=1
    while n>0
        if n%3==1
            x+=z
        elsif n%3==2
            y+=z
        end
        n/=3
        z*=2
    end
    [x,y]
end

def place2num(x,y)
    return nil if x<0 || y<0 || x&y>0 # x|y!=x+y
    n=0
    z=1
    while x>0||y>0
        if x%2>0
            n+=z
        elsif y%2>0
            n+=2*z
        end
        x/=2
        y/=2
        z*=3
    end
    n
end

while gets
    x,y=num2place($_.to_i)
    puts [[0,-1],[-1,0],[1,0],[0,1]].map{|dx,dy| # this order is important
        place2num(x+dx,y+dy)
    }.compact*','
    STDOUT.flush
end

Python

tyama_henae15.py

#!/usr/bin/env python
#http://nabetani.sakura.ne.jp/hena/orde15nohil/
#http://qiita.com/Nabetani/items/705fa83cfbf20377b92f

import sys
if sys.version_info[0]>=3: raw_input=input

def num2place(n):
    x=y=0
    z=1
    while n>0:
        if n%3==1:
            x+=z
        elif n%3==2:
            y+=z
        n//=3
        z*=2
    return (x,y)

def place2num(x,y):
    if x<0 or y<0 or x&y>0: return None
    n=0
    z=1
    while x>0 or y>0:
        if x%2>0:
            n+=z
        elif y%2>0:
            n+=2*z
        x//=2
        y//=2
        z*=3
    return n

try:
    while True:
        x,y=num2place(int(raw_input()))
        a=[place2num(x+dx,y+dy) for (dx,dy) in [(0,-1),(-1,0),(1,0),(0,1)]]
        print(','.join(str(e) for e in a if e is not None))
        sys.stdout.flush()
except EOFError:
    pass

C

• C99準拠のはず

tyama_henae15.c

//http://qiita.com/Nabetani/items/705fa83cfbf20377b92f
//http://nabetani.sakura.ne.jp/hena/orde15nohil/

#include <stdio.h>
#include <stdbool.h>

typedef struct{
    int x;
    int y;
}dir;
const dir D[]={
    {0,-1},{-1,0},{1,0},{0,1} // this order is important
};

void num2place(long long n, long long *px, long long *py){
    long long x=0,y=0;
    long long z=1;
    for(;n>0;){
        if(n%3==1){
            x+=z;
        }else if(n%3==2){
            y+=z;
        }
        n/=3;
        z*=2;
    }
    *px=x;
    *py=y;
}
long long place2num(long long x,long long y){
    if(x<0 || y<0 || (x&y)>0)return -1;
    long long n=0;
    long long z=1;
    for(;x>0||y>0;){
        if(x%2>0){
            n+=z;
        }else if(y%2>0){
            n+=2*z;
        }
        x/=2;
        y/=2;
        z*=3;
    }
    return n;
}
int main(){
    long long n,x,y;
    for(;~scanf("%lld",&n);){
        num2place(n,&x,&y);
        bool first=true;
        for(int i=0;i<4;i++){
            long long m=place2num(x+D[i].x,y+D[i].y);
            if(m>=0){
                if(!first)printf(",");
                first=false;
                printf("%lld",m);
            }
        }
        puts("");
        fflush(stdout);
    }
}